1. Field of the Invention
Solar energy collecting devices are of two types, those with movable parts which track the sun and flat plate collectors. The latter have presented a problem in that it was hitherto necessary for their components to be individually designed and crafted, adding appreciably to the cost. Present day technology in the glass industry would now allow for mass production.
The prime problem associated with solar collectors has been the efficient retention of heat energy or stated conversly the prevention of heat loss. Heat loss occurs in three ways, by convection, by conduction and by radiation. The first means of heat transference, convection, can be eliminated by evacuating the ambient surrounding the heat absorption means. Conduction can be appreciably reduced by eliminating the use of good heat conductors such as metals, and the interfacing of materials with different levels of heat conductivity.
The refocusing of scattered radiation by the concave mirrored surface of the jacket and by the one way reflector coating on the remainder of the inner surface of the jacket, so that it is directed on the blackened heat absorption means, further aids in reducing heat loss. The evacuated ambient reduces deterioration of the mirror, and the efficiency of the blackening means increase heat absorption.
2. Description of the Prior Art
The Abbott U.S. Pat. No. 1,946,184 which discloses a collector designed to move with the sun, having an outer hollow glass highly evacuated tubular body with a blackened copper tube for heat absorption and circulation, in the line focus of an outside parabolic reflector.
The U.S. Pat. No. 2,872,915 to Bowen discloses the use of a secondary transparent reflector opposite the primary reflector to retain the heat waves which bounce off the primary reflector within the collector.
The patent to Godel et al, U.S. Pat. No. 3,227,153, discloses a flat plate collector having a glass evacuated cylinder with heat collecting tubes secured as by metal support and positioning means to the cylinder.